1. Field of the Invention
The present invention relates to a conductive film and a method for manufacturing the conductive film, and more particularly, to a conductive film that is suitable for, for example, a projected capacitive touch panel, a method for manufacturing the conductive film, and a touch panel using the conductive film.
2. Description of the Related Art
A portable electronic apparatus that is typified by a smart phone is provided with a touch panel as a man machine interface. In recent years, a desktop personal computer (PC) or a notebook PC has been provided with a touch panel. In general, since a PC has a larger screen than a smart phone, a touch panel used in the PC requires high transparency and high conductivity.
A touch panel comprises a conductive film (also referred to as a conductive sheet or a conductive layer) in which electrodes that are formed by thin metal wires having a predetermined pattern are formed on a transparent film. In general, the conductive film is made of indium tin oxide (ITO). However, the film made of ITO has the problems that it is difficult to obtain the high conductivity required for a large screen and costs increase.
In recent years, as a conductive film used instead of an ITO film, a conductive film comprising thin metal wires that are formed in a mesh shape and have high conductivity has drawn attention. KR10-2013-0011901A discloses a technique that forms a mesh-shaped groove portion in a surface of a resin layer and fills the groove portion with high-conductivity metal particles to manufacture a conductive film. This technique comprises a step of applying ink mixed with high-conductivity metal particles and a binder onto the surface of the resin layer in which a bank portion and a groove portion are formed, a step of scraping the surface of the bank portion with a squeegee to fill the groove portion with the ink and to remove the ink, and a step of hardening the ink in the groove portion. The conductive film has the advantage that the conductive film is less likely to be oxidized since the groove portion formed in the surface of the resin layer is filled with the metal particles. In addition, the conductive film has the advantage that manufacturing costs are lower than those when a metal film formed by vacuum deposition is etched. The conductive film has drawn attention due to these advantages.